如何通过Angular4下载网页?
我想通过Angular 4下载一个页面。如何通过Angular4下载网页?,angular,http,jsonp,Angular,Http,Jsonp,我想通过Angular 4下载一个页面。 实际上,我想获得YouTube视频的下载链接。 我的代码如下: import { Component } from '@angular/core'; import { NgForm } from '@angular/forms'; import { Jsonp, Http, Response } from '@angular/http'; import { Headers, RequestOptions } from '@angular/http';
实际上,我想获得YouTube视频的下载链接。
我的代码如下:
import { Component } from '@angular/core';
import { NgForm } from '@angular/forms';
import { Jsonp, Http, Response } from '@angular/http';
import { Headers, RequestOptions } from '@angular/http';
import { Observable } from 'rxjs/Observable';
import 'rxjs/add/operator/catch';
import 'rxjs/add/operator/map';
@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent {
title = 'Youtube Direct';
youtubeLink = 'https://www.youtube.com/watch?v=wBBzD_pDags&list=PL3ewn8T-zRWgWGtHzwrvO2ZdCExU7wk8M';
youtubePageHtml: string;
constructor(private jsonp: Jsonp, private http: Http) { }
GetButtonOnClick(): void {
this.jsonp.get(this.youtubeLink)
.map(this.extractData)
.catch(this.handleError);
}
private extractData(res: Response) {
console.log(res);
let body = res.json();
return body.data || {};
}
private handleError(error: Response | any) {
let errMsg: string;
if (error instanceof Response) {
const body = error.json() || '';
const err = body.error || JSON.stringify(body);
errMsg = `${error.status} - ${error.statusText || ''} ${err}`;
} else {
errMsg = error.message ? error.message : error.toString();
}
console.error(errMsg);
return Observable.throw(errMsg);
}
}
但是extractData
从不调用。如何通过Angular 4下载页面?这是因为您需要订阅返回的可观察内容 试试这个:
GetButtonOnClick(): void {
this.jsonp.get(this.youtubeLink)
.map(this.extractData)
.subscribe(
(res: any) => this.youtubePageHtml = res,
(err: Error) => this.handleError,
() => console.log('OnComplete !')
)
}
如果您想了解更多信息:-
-这是因为您需要订阅返回的可观察数据 试试这个:
GetButtonOnClick(): void {
this.jsonp.get(this.youtubeLink)
.map(this.extractData)
.subscribe(
(res: any) => this.youtubePageHtml = res,
(err: Error) => this.handleError,
() => console.log('OnComplete !')
)
}
如果您想了解更多信息:-
-